If they are offering leases, they can offer them for less if they can sell it at a high price when they get it back.
Source: https://www.motortrend.com/news/tesla-cybertruck-electric-pi...
This article has all the details on the design of the truck. It was written before its reveal by journalists who saw the truck and met the team while it was still being designed.
And remember, the cost of an automobile isn't just the material cost, you have to amortize the manufacturing plant and the paint shop. By stressing the stainless steel skin (like an aircraft), Tesla doesn't really need to buy additional material, but they simplify the manufacturing dramatically because they don't need a paint shop and they don't need to assemble a frame.
Cars crumple for a reason and Tesla's new truck seems like an absolute safety disaster even if people feel marginally safer because of it being supposedly bulletproof.